1. Field of the Invention
The present invention relates to a liquid crystal panel with improved outer and/or inner surfaces.
2. Description of the Related Art
Conventional liquid crystal panels are flat panel displays manufactured by bonding together a pair of flat substrates represented by glass, or liquid crystal panels for which substrates such as plastic substrates are used.
FIG. 1 is a model view illustrating the manufacturing flow for a conventional liquid crystal panel. Going down from the top of FIG. 1 to the bottom, first, a substrate 2 that has not an alignment control film coated thereon is prepared according to step S1, an alignment control film 6 composed of a polyimide or the like is formed on the substrate 2 according to step S2, substrate treating such as rubbing is optionally performed according to step S3, bonding with another substrate 3 is performed according to step S4, a liquid crystal is filled in the space according to step S5, and the filling inlet is sealed according to step S6. Thus, a liquid crystal display panel is prepared. The liquid crystal layer 10 is sealed with the substrates 2 and 3, and a sealing member 7 and encapsulant 11.
In the conventional manufacturing process, it is difficult to form an alignment control film on a substrate having a curved surface. In other words, when a substrate has a curved surface, an alignment control film with which the liquid crystal layer comes in contact must have a curved surface. However, the printing step and the spin coating step that are effective for the conventional flat substrates are hard to be used in forming an alignment control film on a curved surface. The situation is the same, in general, if a liquid crystal layer contacting surface is curved, even when the substrates do not have a curved surface. It is to be noted that the “liquid crystal layer contacting surface” according to the present invention means the surface of a layer that a liquid crystal layer actually contacts. For example, when a substrate and a liquid crystal layer are laminated with a filter layer or electrode layer in between, and the liquid crystal layer actually contacts the surfaces of the filters or electrodes, but not the surface of the substrate, the “liquid crystal layer contacting surface” according to the present invention means the surfaces of the filters or electrodes that the liquid crystal contacts. If the surfaces of the filters or electrodes have been subjected to a treatment to give hydrophilicity, the treated surface is the liquid crystal layer contacting surface, for example.
Furthermore, there is a limit in thinning a substrate for the conventional liquid crystal panel. In other words, when a substrate thinner than a certain level is used, the printing process and the spin coating process that are effective in the conventional production processes are hard to be used in forming an alignment control film. In addition, such a substrate is susceptible to plastic deformation at a conventional high-temperature baking treatment, while a low-temperature treatment results in a low level of alignment control, leading to an insufficient reliability in the electric performances.
Accordingly, there are various technical limitations caused by the fact that the installation of the alignment control film is indispensable.
On the other hand, regarding technologies for enhancing the alignment properties of a liquid crystal, there are a liquid crystal existing as independent particles in a ionizing radiation-cured resin matrix (for example, see Japanese Unexamined Patent Application Publication No. 5-113557, claims), a polymerizable monomer having an alkyl side chain being cured with a liquid crystal (for example, see Japanese Unexamined Patent Application Publication No. 6-265858, claims), a polymeric network structure-coated layer (for example, see Japanese Unexamined Patent Application Publication No. 6-289374, claims), a liquid crystal material in which a photopolymerizable acrylate having a liquid crystal skeleton structure is included (for example, see Japanese Unexamined Patent Application Publication No. 8-15707, claims), etc. However, it is believed that omission of the alignment control film has been still an unanswered technology.